Tube retainer



FIG. 1 is a perspective view of a tube retainer incorporating the designof our invention;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a left side elevational view thereof, the right side viewbeing a mirror image thereof; and,

FIG. 4 is a top plan view thereof.

The features of the tube retainer shown in phantom lines are notelements of the design of our invention.

The ornamental design for a tube retainer, as shown and described.